Flexible ski



Dec. 1, 1953 B. P. coULsoN, JR

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Filed Dec. 5l, 1948 Mm. uw ww, WMU

nvllloooo Patented Dec. i, 1953 NEED STATES ATENT OFFICE FLEXIBLE SKI Bevis P. Coulson, Jr., Schenectady, N. Y.

Application December 31, 1948, Serial No. 68,621

4 Claims.

This invention relates to a ski and more paricularly to a ilexible ski adapted to provide smooth travel over uneven snow.

In general it can be said that a ski should be constructed to provide even weight distribution on the surface being traversed, to provide ilexibility enabling the ski to accommodate itself to irregularities in the surface being traversed, and to provide minimum weight consistent with strength. Even weight distribution is usually obtained by the ski a camber or arch which is straightened out when the skiers weight is applied to the ski. Flexibility has heretofore depended largely upon the inherent resilience of the material of which the ski is constructed. However there is a decided tendency for conventional metal or wooden skis to submarine and furrow into a snow ridge because the ski is too stiff to permit the forward end to raise sufficiently to go over the ridge. To provide smooth travel over uneven snow, flexibility at the forward and rear ends of the ski is of course essential and, at the same time, flexibility at the center portion of the ski must not be too great i. e., only suicient to straighten out the camber and provide even weight distribution.

it is, therefore, an important object of my invention to provide a new and improved ski having flexibility at its forward and rear ends to provide smooth travel over uneven snow, the flexin bility at the center or the ski being sufiicient to provide even weight distribution on the surface being traversed. Other objects of my invention are to provide a ski having means to control the flexibility of the ski and to provide a ski having minimum weight consistent with strength.

Briely stated, my invention comprises a ski having a series of longitudinally extending slots arranged in the body of the ski so'that, at intervals along the length of the ski, the top and bottom surface members of the ski are not rigidly connected together. By virtue of this construction, the ski can ilex much more readily than if the ski were a solid body. Too much iiexing, however, can result in buckling so flexing is controlled by providing, in each longitudinal slot, a stop member whichv will limit llexing to an amount insufficient to cause buckling.

The foregoing and other objects and advantages of my invention will become more apparent from the following detailed description taken in conjunction with the attached drawing in which:

Fig. 1 is a side view of a metal ski showing one embodiment of my invention;

Fig. 2 is an enlarged side view of a portion of the 4ski shown in Fig. 1;

Fig. 3 is a cross-section view taken on line 3--3 of Fig. 2;

Fig. 4 is an enlarged side View similar to Fig. 2 showing another embodiment of my invention;

Fig. 5 is a cross-section view taken on line 5-5 of Fig. 4;

Fig. 6 is a side View of a wooden ski showing still another embodiment of my invention;

Fig. 7 is an enlarged side view of a portion of the ski shown in Fig. 6; and

Fig. 8 is a cross-section View taken on line 8-6 of Fig. 7.

Referring to the metal ski illustrated in Figure l, it will be observed that the ski is in conventional overall form having a bottom, or planing, surface member I which is arched t0 provide even weight distribution and a top surface member 2, likewise arched, which supports a foot plate 3. Bottom I and top 2 are connected together at the front and rear ends of the ski as indicated at l and 5. Intermediate these ends are a plurality of rigid spacers 6 which connect bottom I and top 2 together at intervals thereby deilning what I term a plurality of longitudinal slots l located along the length of the ski from adjacent the front end 4 to adjacent the rear end 5.

An enlarged view of a section of the ski containing one of the slots l is shown in Figure 2. In this ligure, 8 is a portion of the top surface member 2 and 9 is a portion of the bottom surface member I. Between the spacers 6, portions 8 and 9 are not rigidly connected together and except for the action of the stop member I0, to be described later, only the inherent stiffness of portions B and 9 limits flexing of this section of the ski. By virtue of this construction of the various slots 1 it is obvious that the front and rear ends of the ski can flex more readily with respect to the center of the ski than if the ski body were a solid member i. e., if bottom I and top 2 were rigidly connected together throughout the whole length of the ski.

Ii the portions 8 and 9 were entirely unsupported between the spacers 6 it is possible that buckling would occur if the ski were subjected to a sudden jolt. This could occur, for example, at

a slot 'I adjacent the forward end floi the ski if the forward end hit an obstruction tending to force the end sharply upward. The tendency here would be for the portion 8 at such a slot to buckle inward toward the portion 9. To forestall such buckling, for all practical purposes, the stop member In is provided. This stop member,

located approximately midway of the length of slot l', is a fairly dense rubber block II, substantially the size of a spacer 6, containing a hollow metal dowel I2, see Figure 3. Since the block Il is resilient it allows initial flexing of portion 8 toward portion 3 rather freely, but if this llexing tends to become excessive the block, through the action of dowel I 2, tends to become rigid. In this situation, the unsupported length of portions 8 and 9 is more than halved whereby the portions 8 and 9 are much more rigid and will resist further flexing more effectively. The hollow meta-l dowel I2 is preferably from 1/3 to 1/2 the height of the block II. Io insure correct inward flexing of the portion il at the outset, this portion is bowed slightly inward toward portion 9 as can be observed from an inspection of Figure 2. The portions 8 and 9 are of substantially equal length and approximately parallel.

In Figures 4 and 5, another embodiment of my invention is illustrated in which the metal dowel I2 is dispensed with and stop action is achieved by virtue of a fairly dense rubber block I3 in conjunction with a sponge rubber filler I4 for the remainder of the slot not lled by the block I3. In Figures i and 5, portion I5 corresponds to portion 8 of Figures 2 and 3, portion I6 corresponds to portion 9, spacers I 1 correspond to spacers 6, and slot I3 corresponds to slot The action of block I3 plus ller I 4 is essentially the same as that described for stop I except that the latter tends to become more rigid because of the dowel I2. However, the use of the filler I i has the advantage that snow cannot get into the slot IS and interfere with the stop action. Block I3 and illler I 4 are bonded directly to the metal portions I and I6 the same as block II is directly bonded to metal portions 8 and 9.

The wooden ski shown in Figure 6 of the drawing discloses still another embodiment of my in vention, In this figure, the ski body I9 has a bottom, or planing, surface 2 and a top surface ZI which supports a foot plate 22. To' provide even weight distribution, the ski body is given a camber. or arch, as shown in Figure 6.

At intervals along the length of the body I9, elongated slots 23 and 2li are provided. These slots extend clear through the ski body laterally and are elongated lengthwise of the ski. One of the slots 24 is adjacent the rear end 25 of the ski and the other slot 2f! is nearest the front end 26 of the ski. These slots 24 are longer than the intermediate slots in order to give greater flexibility to the front and rear ends of the ski than to the center of the ski.

To control flexing of the slot walls, one stop member 2 is provided in each of the slots 23 and two stop members 27 are provided in each of the slots 2G. Referring to Figure 7 of the drawing, stop member 21 is shown as being attached to the upper wall 23 of a slot 23 by means such as screw 29. The stop member is positioned approximately midway of the length of the slot 23 and is spaced as indicated. at 3! from the lower wall 3I of the slot. Walls 28 and 3I correspond to portions 8 and 9 of Figures 1 3 and the word portion in the claims appended hereto is intended to refer to a slot wall member. These walls 28 and 3l are of substantially equal length and are approximately parallel.

Because of the space 30, which is approximately one third the height of slot 23, initial flexing of the ski in the vicinity of the illustrated slot is resisted only by the inherent stiffness ofthe slot walls. This provides initial flexibility. Continued flexing of wall 28 toward wall 3| causes stop 21 to contact wall 3| thereby more than halving the unsupported length of the Walls 28 and 3| and thus substantially increasing resistance to further flexing. The stop 21 is made of suitable material, such as hard rubber, and extends substantially the width of the slot as shown in Figure 8. The two stops 2l in each of the slots 24 are positioned to divide the length of the slot approximately into thirds and the action of these stops is as described in reference to Figure '1. Parts of the ski body I9, such as are indicated at 32, can be considered broadly as spacers and generally equivalent in action to spacers such as the spacers 6 shown in Figures 1-3.

In the various embodiments of my invention described above it is apparent that the skis disclosed have flexibility by virtue of the slot arrangement and yet are not overly flexible because of the stop action provided in the slot arrangements. By judicious choice of the number of slots to be employed the ski can be made more or less flexible. Stop action can be achieved in a number of ways, as described, the central idea being to provide a stop arrangement which allows initial flexibility and then increases resistance to further flexing in order to prevent buckling of the ski. By buckling is meant, of course, breaking of the ski the same way that a piece of wood breaks when one props it up against a support and then steps on it in the middle to break it in two. Preferably, initial flexing is permitted substantially unhampered by the action of the stop members but, in case the flexing continues. these stop members tend to become essentially rigid thereby materially increasing the stillness of the ski and increasing its resistance to further flexure.

While I have described and illustrated several embodiments of my invention, I wish it to be understood that I do not intend to be restricted solely thereto, but that I do intend to cover all modifications thereof which would be apparent to one skilled in the art and which come within the spirit and scope of my invention.

I claim:

l. A metallic ski comprising a bottom member having a planing surface and a top member supporting a footplate, said members being united at the front and rear ends of the ski and spaced apart along each side of the ski intermediate said ends, spacers defining, together with said bottom and top members, a plurality of slots spaced lengthwise of said ski, and a resilient stop member positioned in each of said slots approximately midway the length of the slot, said stop member being constructed and arranged to limit deflection of said bottom and top members toward each other.

2. A metallic ski comprising a bottom member having a planing surface and a top member supporting a footplate, said members being united at the front and rear ends of the ski and being spaced apart intermediate said ends, spacers defining, together with said bottom and top members, a plurality of slots spaced lengthwise of said' ski, and a resilient stop member positioned in each of said slots approximately midway the length thereof, saidv stop member having a substantially rigid member embedded therein and being attached to the bottom and top members whereby deflection of said bottom and top members toward each other is limited by said stop member.

3. In a flexible ski, a plurality of sections each comprising a ski bottom portion, a ski top portion, said portions being spaced apart at each side of the ski, spacers defining, together with said portions, a slot elongated in a direction lengthwise of said ski, and a resilient stop member positioned in said slot, said stop member being attached to said bottom and top portions whereby deection of said portions toward each other is limited by said member.

4. In a flexible ski, a section comprising a ski bottom portion, a ski top portion, spacers dening, together with said portions, a slot elongated in a direction lengthwise of said ski, and a resilient stop member positioned in said slot approximately midway of the length of the slot, said stop member having a substantially rigid member embedded therein whereby deeetion of said bottom and top portions toward each other is limited by said stop member.

BEVIS P. COULSON, JR.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 748,172 Draper Dec. 29, 1903 1,678,579 Vincent July 24, 1928 lo 2,362,380 Kallstrom et al. Nov. 7, 1944 2,526,137 Hunt Oct. 17, 1950 FOREIGN PATENTS Number Country Date 5 70,053 Norway Feb. 11, 1946 790,310 France Nov. 19, 1935 

